In a communication network, a user may be connected with equipment of the user through a connection service provided by an operator network, for example, the user may be connected with two routers through an optical connection service provided by an optical network operator. In the case that a control plane is introduced to a network, the control plane defines a general protocol, which may implement fast automatic creation of user services. The protocol includes two parts: a call and connection, where the call is used to implement functions such as authentication of a user access right and a switch of link information at a user side, and the connection is mainly used to provide the user services, that is, perform resource distribution and reservation in the operator network.
FIG. 1 is a schematic diagram of a call model in the prior art. As shown in FIG. 1, networks at two client side are accessed to a network at a server side through a User Network Interface (UNI) link, and the network at the server side sends a signal at the client side to another end. In nodes at the two ends of the UNI, a node in the network at the client side is called “UNI-C”, and a node in the network at the server side is called “UNI-N”.
Before creating a connection between UNI-Cs, a call is first created to implement route information interaction of the two ends and an admission control function of the network at the server side, and after the call is successfully created, the corresponding connection is created. A call initiated by equipment of the network at the client side may be processed by access equipment of the network at the server side, or may also be processed by a special unit, where the unit used for processing a call is called a Call Manager.
As shown in FIG. 1, before creating a connection between a UNI-C1 and a UNI-C2, the UNI-C1 initiates a call creating procedure, that is, sends a call creating request message to a UNI-N1, where the massage carries related information such as a requested bandwidth. The UNI-N1 determines whether to allow the call to be created according to a preconfigured policy, and if allowed, the UNI-N1 forwards the call creating request message to the UNI-N2, and then the UNI-N2 forwards the call creating request message to the UNI-C2. The UNI-C2 examines information such as a local UNI link bandwidth, and if the requirements are met, a call creating response message is returned to the UNI-N2, where, the message may carry information of local available UNI link, for designating an available link during connection creating. The UNI-N2 forwards the call creating response message to the UNI-N1, and then the UNI-N1 forwards the message to the UNI-C1, and finally, the call is successfully created. In the preceding procedure, the UNI-C1, UNI-N1, UNI-N2 and UNI-C2 all have a call processing function, that is, the function of a call manager is implemented.
After the call is successfully created, a connection creating procedure is initiated, For example, the UNI-C1 sends a connection creating request message to the UNI-N1 to designate a connection created onto the UNI-C2, and designate a remote link. The UNI-N1 calculates an appropriate route and creates the connection to the UNI-C2.
In the implementation of the present invention, the inventor finds that the call model in the prior art at least has the following problems. An existing General Multi-Protocol Label Switch (GMPLS) call model merely supports end-to-end call processing, in the case that a connection service passes through multiple networks at a server side (it is supposed that each network at the server side is divided into one domain), the existing call model does not support call section processing performed by each domain, therefore, functions such as inter-domain link selection and admission control of each domain are not supported.